Advertising of products and services is a world-wide, multi-billion-dollar industry. Indeed, because sales of many goods depend substantially on brand name recognition with customers, modern consumers are regularly exposed to a wide variety of images and sounds all intended to communicate to them the names or qualities of a particular merchant's products.
Point of purchase ("P.O.P.") panels or posters are one important vehicle for communicating advertising and marketing information to consumers. Such panels are often attached to a storefront window and may be designed, for example, to educate customers about the merchant's products or to encourage potential customers passing by a retail location to enter the premises. Advertising posters may also be mounted in non-point-of-purchase locations such as on buses, billboards, or as broadsides.
In the past, P.O.P. panels have typically been printed on an opaque substrate and affixed to storefront windows by either pressure sensitive adhesive or static cling. Opaque panels, however, suffer from several significant drawbacks. First, when hung in a shop window, such panels block much of the sunlight that would otherwise enter the store. Moreover, in certain retail environments, such as fast-food restaurants, it is desirable that customers be able to look outside while, for example, eating at a table near the window.
To overcome these drawbacks, it has been proposed to print P.O.P. panels on a perforated layer of a multi-layer material. When viewed from one side, the resulting panel presents the printed design. When viewed from the other side, however, the perforated panel is substantially see-through, and the printed design is substantially not visible. Persons facing this second side of the panel (e.g., persons looking out the front window of a restaurant) are thus able to see through the panel, but cannot see the printed design.
But these prior art multi-layer panels also suffer from severe drawbacks. First, the multi-layer panels of the prior art are expensive and difficult to make. For example, one commercial embodiment of prior art multi-layer stock comprises at least four layers: a perforated 8 mm white/black vinyl laminate, a pressure-sensitive adhesive on one side of the laminate, a perforated 90# staflat release liner covering the adhesive, and an unperforated thin plastic membrane attached to the release liner.
The unperforated membrane is necessary because commercial printers employ suction to grip and move the workpiece from one printing station to the next. Suction, however, cannot be employed to grip and move perforated sheets. An unperforated membrane is therefore necessary to permit suction to grip the multi-layer material.
Manufacture of multi-layer materials like the one described above is both time consuming and expensive. Consequently, the cost of these materials is significantly higher than that of ordinary banner material. Moreover, because significant spoilage must be expected during printing, many multi-layer sheets do not yield usable panels and must be thrown away. Therefore, the cost of producing large quantities of display panels using such prior art multi-layer materials is often prohibitively expensive and offers little or no economies of scale.
Another drawback of prior art multi-layer panels is that interior and exterior panels cannot be printed on the same multi-layer stock. In particular, the multi-layer stock described above is not suitable as an interior-mounted panel because it is not possible to print a design on the side of the laminate that is coated with adhesive. Consequently, interior panels are typically made from a different multi-layer material than the one described above. For example, one commercially available material for printing interior panels comprises a 6 mm perforated clear vinyl layer, a layer of adhesive, and a perforated release liner. The perforated release liner is covered by an additional non-perforated membrane to permit suction to grip the sheet during printing and processing. With this panel, the desired design is printed in reverse on the side of the laminate that is not coated with adhesive. The printed design is then covered by a layer of white ink to set up the image and then black backed. Because the panel and adhesive are clear, the image can be seen through the panel when the panel is displayed in, for example, a store window.
Thus, another disadvantage of the prior art is that it requires different stock for interior and exterior panels. Consequently, a decision must be made prior to printing as to whether the panel to be printed will be mounted on an exterior or interior surface.
It has also been proposed to manufacture P.O.P. panels having the bi-directional properties described above by printing a silhouette pattern, rather than a complete design, on the panel. Because the silhouette pattern comprises both opaque and transparent areas, the design embodied in the silhouette pattern can be seen by persons on one side of the panel, while the panel appears substantially see-through to persons standing on the other side of the panel. This prior art technique, however, also suffers from a serious drawback in that the design must be printed as a silhouette pattern, a difficult and expensive process.
There is therefore a need in the art for high quality display panels that are simple and inexpensive to produce, but that exhibit the bi-directional qualities described above.